Air cleaner



` A. W. MILLER Feb.- 6, 1934.

AIR CLEANER Filed Sept. 24, 1951 2 Sheets-Sheet l iff/2 ATTORN EY A. w. MlLLx-:R

Feb. e, 1934;

AIR CLEANER Filed sept. 24, 1931 2 Sheets-Sheet IN EN BYf/lf/ To. j

ATTORNEY Patented Feb. 6, 1934 UNITED STATES PATENT OFFICE AIR CLEANER Arthur W. Miller, Milwaukee, Wis.

'Application September 24, 1931 Serial No. 564,782

16 Claims.

'10 dium, comprising a loose mass of non-absorbent material, such as steel wool, crinkled wire, or the like, through which the air is drawn, and into which oil is admitted for the purpose of absorb- `ing and carrying off impurities from the air passing therethrough and for the additional purpose of keeping the filter clean. Such cleaners also ordinarily include an oil reservoir from which the oil is supplied to the filter and to which Y the dirt laden oil is returned from the lter.

A In prior cleaners of the ty`pe mentioned, the

oil is usually transmitted directly from the reservoir to the iilter by the action of the incoming air, so that the amount of oil Supplied to the 4filter vvaries with the rate of air flow. Such cleaners have not proven entirely satisfactory however due to an inability to maintain a proper supply or a proper circulation of oil to and through the lter, under the various conditions y of operation to which they are subjected in ncrvmy mal use. For instancef'rwhen applied to an internal combustion engine, the rate of 110W of incoming air varies greatlyyvith engine speed and load. During idling or at slow speeds under light or moderate load the rate of air flow is but a 36l small fraction of the rate at high speed or at full load operation, and the amount of oil supplied to the iilter varies accordingly. Consequently, during idling, the amount of oil supplied to the filter is insucient to eectually clean the air or to keep the iilter clear of obstructing matter deposited from the air; and at high speed or l full load operation the supply of oil is excessive and is carried oi by the air, thereby ldepleting.

supply of oil regardless of the rate of ow of air therethrough. v Y .Another object is the provision in an air cleaner of improved means for eiecting continuous removal of dirt laden oil from the lter.

Another object is the provision in an air cleaner of a novel combination of parts so arranged as to maintain a substantially continuous circulation of oil through the lter in an improved manner and in such quantities as to eiectually4 clean the air and to 'remove from the lter impurities received from the air.

Other more specic objects and advantages 05 will appear from the following description of an illustrative embodiment of the present invention.

In the accompanying drawings:-

Fig. 1 is a Vertical sectional view of an air cleaner constructed in accordance with the present invention;

Fig. 2 is a horizontal sectional view on the line 2-2 of Fig. 1;

Fig. 3 is a sectional view, on a larger scale, taken along the line 3-3 of Fig. l; andV Fig. 4 is a sectional view on the line 4 4 of Fig. 1.

The air cleaner selected for illustration comprises a cylindrical housing or shell 10, preferably of sheet metal, closed at the lower end by a cup-shaped container 11 removably applied thereto. The container 11 provides an oil reservoir which is ordinarily lled to about the level indicated in Fig. 1. The upper end of the shell is closed by a hollow outlet tting l2, preferably removably attached by bolts 13, or otherwise, to a ring 14 xed to the shell.

A discharge conduit 15, connected to the tting, leads to the intake of an engine carburetor 8. Air is admitted to the lower end of the shell preferably through a conduit 16 which communicates with the shell through a fitting 17 and side opening 18, and which is conned between the fitting 17 and a fitting 19 preferably formed integral with the ring 14. 95

A iiltering medium 20, preferably comprising a loose mass of non-absorbent material, such as steel Wool, crinkled wire or the like, extends across the shell "10 above the air inlet opening 18 and below the outlet tting 12. In this instance the ltering material surrounds a central tube 21 depending'from and supported by the down-turned end 22 of a goose-neck 23, preferably formed in` tegral with the ring 14. The lower portion of the ltering material is surroundedby a cylindrical shell 24.- spaced inwardly from the main -shell 10 to form a drain passage 25 for a purpose to be later described, the material beingl further conned between a substantially dat bottom screen 26 and a top screen 27 preferably 110' of conical form and sloping downwardly and outwardly over the drain passage 25. It will, of course, be understood that atmospheric air entering the conduit 16 and opening 18 is drawn upwardly through the lter 20 by the suction transmitted from the engine through the conduit 15.

The inner shell 24 is provided with a depending apron 28 of substantially cylindrical form which extends downwardly into the body of oil in the reservoir and which is spaced slightly from the main shell 10 to provide a continuation 25 of the drain passage 25. As indicated in Figs. 1 and 2, that portion of the apron 28 adjacent the inlet opening 18 isA cut away and the edges 29 thereof are bent outwardly against the shell 10 and secured thereto by soldering or otherwise. That portion of the inner shell 24 above the opening 18 is anged, as indicated at 30 in Fig. 1, and also secured to the shell 10.

The edges 29 and flange 30 are preferably tightly joined to the shell 10 in such manner as to prevent the admission of air to the passages 25 and 25', the lower end of passage 25 being sealed by the oil in the reservoir. Due to the fact that the upper end of passage 25 is exposed to the suction in the upper end of the shell 10, oil rises from the reservoir into the passage 25', and to reduce to a minimum the amount of oil thus withdrawn from the reservoir the passage 25 is very narrow.

A circular ring or baiiie 31, preferably of dished form, mounted within .the apron 28 above the inlet opening 18, serves to distribute the incoming air throughout the bottom of the filter 20, and also to increase the velocity of flow at that point.

Provision is made in the lter shown for effecting a substantially continuous discharge of oil into the air stream, as it issues through the central opening in the baffle 31, so that the oil thus discharged is carried upwardly by the air into the lter. Although this might be accomplished in various ways, the novel form of pneumatic oil elevator which will now be described has proven entirely satisfactory for the purpose. v

The oil elevator shown comprises a tube 32, sealed at its upper end by a plug 33 xed therein and connected at'its lower end to a valve chamber 34. The tube 32 is disposed within the tube 21 and is supported by a threaded shank 35 on the plug 33, which is screwed into the end 22 of the goose-neck 23. The tube 32 and connected parts may thus be readily removed for inspection, replacement, or repair by rotating the tube and shank 35 in such direction as to unscrew the same. The tube 32 communicatesthrough a restricted passage 36 in the plug 33, with a passage 37 in the goose-neck, which passage in turn communicates, through a tube 38, with the intake manifold 9 of the engine at a point beyond the engine carburetor. During operation a partial vacuum is thus maintained in the tube 32 by suction transmitted through the restricted passage 36 from the intake manifold, regardless of whether the engine carburetor is open or closed.

The valve chamber shown at 34 is disposed below the lter 20 and is in the form of a hollow disk, having a depending peripheral lip 39, and also having a plurality of outlet ports 40 in the top face thereof. The ports 40 are covered and normally closed by a circular flap valve 41 of flexible material, such as leather, which functions to prevent admission of air to the valve chamber, but to permit the escape of oil therefrom. In this instance the valve is releasably retained in place by the down-turned inner ange 42 of an overlying protector ring 43. The valve chamber 34 is fixed to the lower end of the tube 32 by appropriate means such as an upturned ange 44 which is fixed to the interior of the tube.

The tube 32 and valve chamber 34 constitute an auxiliary reservoir into which oil is introduced through an oil elevating tube 45 and from which oil is discharged beneath tlfe iiap valve 41. The oil elevating tube 45 is supported by the bottom of the valve chamber 34. It extends upwardly nearly to the top of the tube 32 and downwardly into a narrow well 46 to a point below the oil level in the reservoir. The interior of the tube 45 is preferably divided bysuitable lpartitions into a plurality of narrow channels 47.

The well 46 in this instance comprises/ a tube, only a little larger than tube 45, supported by and depending from the bottom of the valve chamber 34, the lower end of the tube being closed by a cap 48 having a narrow port 49 through which oil is slowly admitted thereto. The upper end of the well is open to the air in the housing through suitable side ports 50.

As a result of the partial vacuum or suctiorl maintained in the tube 32 by manifold suctionl oil passes upwardly through the elevating tube 45 from the well 46 and discharges substantially continuously into the tube 32, to thereby flood the valve chamber 34 and maintain a column of oil in the tube 32. The column of oil thus maintained is of sufficient height to overcome the sustaining eiect of the partial vacuum in the tube 32, with the result` that there is a substantially continuous escape of oil fromv the base of this column through the ports 40, the escaping oil seeping beneath the flap valve 41 and dripping from the lip 39 into the stream of air passing upwardly through the baille 3l.

It will be noted that the rate of oil admitted to the well 46 through the narrow port 49 is so restricted that withdrawals from the well through the elevating tube 45 reduces the 'amount of oil in the well causing the same to assume a low,v

minutely fluctuating level adjacent the lower end 5l of the elevating tube. As this level fluc-- tuates below the end 5l of the tube, small quantities of air enter the tube from the well to thereby aerate the narrow columns of oil within the narrow tube channels 47 and thus facilitate the upward travel of the oil therethrough. By reason of this aerated condition of the oil in tube 45, the degree of vacuum in tube 32, required to elevate oil from the lower reservoir through the tube` 45, is not so great as to prevent the discharge of oil from the tube 32 in the manner above described.

The air discharged from the uper end of the tube 45 escapes through the passages 36 and 3'? and tube 38 to the engine manifold. An appropriate bale 52, mounted over the upper end of tube 45 precludes the entry of oil from the tube 45 into the passage 36. In this instance the baille 52 comprises a sheet metal cone supported on brackets 53, preferably fixed to the outside of and below the end of the tube 45, so that oil will drain from the baffle and brackets into the tube 32 rather than into the tube 45.

It will also be noted that the oil that drips substantially continuously from the lip 39 of the `valve chamber 34 is immediately picked up and carried directly into the filter 20 by the upward ow of air through the baffle 31, so that the rate of oil transmitted to the filter is not governed by the rate of air flow but by the rate of discharge of oil from the valve chamber 34, except during occasional momentary periods of excessive discharge when some of the oil may pass through the air stream and fail to reach the lter. Except for momentary fluctuations which do not materially affect the functioning of the cleaner and which may therefore be disregarded, the rate of discharge of oil from the chamber 32 is automatically maintained substantially constant, or at least between narrow limits, as will appear from the following observations.

Since the oil elevating tube 45 receives its entire supply of oil from the well 46, the rate at which oil passes upwardly through tube 45 into tube 32 is limited by the rate at which oil is admitted to the Well through the narrow port 49, that being governed primarily by the size of the port and, to some extent, by the depth of the port below the level of oil in the reservoir, although, if positioned two inches below the normal reservoir level, it has been found that a one inch rise in that level will not materially change the rate of flow through the port. Since the tube 32 always communicates with the high suction or partial vacuum in the engine intake manifold, the degree of vacuum maintained therein is suflicient, under all operating conditions, to maintain a maximum flow of oil upwardly through the tube 45. The tube 32 is therefore continuously supplied with oil at a substantially constant rate, as governed by the port 49.

The restricted passage 36 between the tube 32 and manifold suction prevents the creation of an excessive degree of vacuum within the tube 32, and thereby prevents a complete ooding of the tube 32 by the column of oil therein, which would otherwise occur if the degree of vacuum therein were permitted to approximate the degree of vacuum within the engine manifold. In this connection it will be noted that the air discharged into tube 32 from the tube 45 tends to reduce the vacuum in the tube 32, and that the size of passage 36 is so selected as to carry off this air at a rate suicient to maintain the desired degree of vacuum therein. Although the degree of vac# uum, thus maintained, varies somewhat with changes in manifold suction, such variations are very slight.

The height of the column of oil sustained within the tube 32 corresponds at alll times to the dif- Aference between the internal air pressure or degree of vacuum within the tube and the external air pressure or degree of vacuum surrounding the valve 4l. For any given engine load and speed that difference is constant, so that the height of the oil column remains constant, consequently the rate of discharge of oil from the valve chamber corresponds to the rate of oil delivered to the tube 32 from the tube 45. As above pointed out, this rate is governed by the port 49 in the well 46, so that for any given engine speed and load the rate of discharge fr/m the chamber 34 is substantially constant.

Furthermore, although slight changes occur in the external air pressure or partial vacuum surrounding the valve 41 with changes in the rate of fldw of air through the cleaner, as a result of changes in engine speed or load, and although similar. slight changes also occur in the internal air pressure or partial vacuum within the tube 32, as 'a result of changes in engine speed or load, these changes are immediately compensated for by a change in the height of the Yoil column in the tube 32, causing a momentary changein the rate of oil discharge. but as soon as the oil column has readjusted itself to the changed conditions the height thereof again becomes constant and the oil discharge rate again equals the rate of oil supply to the tube 32. Therefore, the rate of oil supplied to the filter is governed by the port 49 in the well 46 and remains substantially constant under all conditions of operation, except for momentary fluctuations which occur at the instant of change in those conditions.

As hereinabove indicated, the fall or rise of the oil level in tube 32, as the oil column adjusts itself automatically to changes in operating conditions, is of course, accompanied by a momentary increase or decrease in the rateof discharge of oil from the valve chamber 34T For instance, if, due to changes in operating conditions,1the suction within that area surrounding the va e 41 be suddenly increased or the suction within the tube 32 be suddenly decreased, or both, the oil column in tube 32 will immediately lower, causing an increased discharge of oil through the valve 41, and if such change is pronounced and occurs very abruptly the amountof oil discharged may, for an instant, be so great that some of itmay pass through the air stream and fail to reach the filter; and, on the other hand, if the suction within that area surrounding the valve 41 be suddenly decreased or the suction within tube 32 be suddenly increased, or both, the discharge of oil from the valve 4l decreases and may momentarily 105 cease until the height of the oil column in tube 32 has increased, to correspond to the new condition, by oil supplied through the tube 45. These uctuations in the rate of discharge'of oil from the valve 41, however, are only occasional and momentary departures from the normal discharge rate, which rate is substantially the same whether the engine be operating at high or low speed or under no-load or full-load condition.

The oil, substantially continuously supplied to the lower inlet end of the lter20 in the manner above described, adheres rather tenaciously to the material of the lter, and, under the -inuence of the air ow through the filter, works its way upwardly toward the discharge end thereof, so that throughout the lter the material thereof is coated with oil to which impurities in the air adhere and by which these impurities are absorbed and retained. This upward progress of the oil through the lter continues, carrying the entrapped impurities with it, until the upper top screen 27 is reached. The dust laden oil clings to this screen and drains downwardly toward the base thereof where it accumulates and ultimately flows by gravity into the drain passage 25. From the drain passage 25 the dust laden oil is returned to the oil reservoir through the narrow passage 25'.

-It will thus be noted that the sloping discharge end of the filter greatly facilitates the removal of the dust laden oil from the filter, and that thetapered or conical form thereof affords -a relatively large drain area for the oil over which the oil may spread in such manner as to avoid interference with the air discharging therethrough;

The oil reservoir -also functions as a trap or f settling chamber for theimpurities carried' there- *y to by the returning oil, and in order to' avoiddisf turbance of the body of oil therein by thefblast of incoming air, a shield 54 is preferablypro@ vided below the air inlet opening 1,8. this instance the shield 54 is supportedby,atube` 55? fixed to and depending fromthe bottom' o fj'tlse` valve chamber 34.,V The tube ,55also protects the' 15? ports 50 and Well 46 against the blast of the incoming air.

Although I have produced successful air cleaners embodying the present invention in which the parts were variously proportionedand arranged, I shall cite, as an example, a particular air cleaner having the following specific proportions and which has been applied to and successfully operated in connection with a cornmercial form of gasolineengine having a displacement of 648 cubic inches at 2200 revolutions per minute.

In the particular cleaner mentioned the parts were proportioned and arranged substantially as shown in the accompanying drawings, the main housing or shell 10 having an inside diameter of 8&2- inches; the well 46 having an inside diameter of l; inches, and being immersed to a depth of 11/2 inches below the normal (with the engine at rest) oil level in the base of the housing; the port 49 in the bottom of the well being 52 inch in diameter; the oil elevator tube Ll5-having an inside diameter of inches and extending upwardly to a height of approximately 12 inches from the bottom of the well; the tube 32 having an inside diameter of 29g inches, the length of this tube plus the depth of the valve chamber being substantially 11 inches, so that the oil discharged from said chamber at a point approximately 31/2 inches above the normal oil level; and the restricted port 36 atthe top of the tube having a diameter of .0635 inches.

Various changes may be made in the embodi ment of the invention hereinabove described Without departing from or sacrificing the advantages of the invention as dened in the appended claims.

I claim: f

1. In an air cleaner foriinternal combustion engines of the type having a carburetor, said cleaner comprising the combination of a lter, means for directing air through said filter by carburetor suction, means for delivering a dust absorbing liquid to said llter, and suction means operated independentlyV of carburetor suction for supplying liquid to said delivery means.v

2. In an air cleaner for internal combustion enginesv of the type having a carburetor and intake manifold, said-'cleaner comprising means for directing air through said filter by carburetor suction, and means energized by manifold suction independently of said carburetor for delivers ing a dust absorbing liquid into a zone of admission to said filter.

3. In an air cleaner for the purposes described the combination of a lter through which air passes, a liquid reservoir, a well having a restricted liquid admission passage below the level of liquid in said reservoir through which said well is supplied with liquid, and fluid actuated means supplied from said well for delivering liquid to saidfllter.

4. In an air cleaner for the purposes described the combination of a filter ,through which air passes, a liquid reservoir, a well having a restricted liquid admission passage below the level of liquid in said reservoir through which said well is supplied. with liquid from said reservoir. means including an auxiliary reservoir through which liquid is delivered to said filter, and means supplied from said well for supplying liquid to said auxiliary reservoir.

' 5. In an air cleaner the combination of a filter through which air passes, a liquid reservoir, a well having a restricted liquid admission passage below the level of liquid in said reservoir through which said well is supplied with liquid from said reservoir, means including a vacuum chamber through which liquid is delivered to said lter, and suction means supplied from said well for supplying liquid to said chamber.

6. In an air cleaner the combination of a lter through which air passes, a liquid reservoir, a Well having a restricted liquid admission passage below the level of liquid in said reservoir through which liquid is supplied thereto from said reservoir and also having an air inlet, means including a vacuum chamber through which liquid is delivered to said lter, and means energized by the vacuum in said chamber for transferring a mixture of liquid and air from said well to said chamber.

7. In an air cleaner the combination of a filter through which air passes, a reservoir, means including a vacuum chamber through which liquid is delivered toi said lter, means energized by the vacuum in said .chamber and supplied from said reservoir for supplying a mixture of air and oil to said chamber, suction transmitting means connected with said chamber for maintaining a partial vacuum therein, and a restricted passage between said last named means and chamber for limiting the degree of vacuum thus maintained in said chamber.

8. In an air cleaner the combination of a filter through which air passes, a reservoir, a vacuum chamber, means energized by the vacuum in said chamber for transferring liquid from said reservoir to said chamber, and valve means through which liquid is delivered to said iilter from said chamber, said valve means being effective to prevent admission of air therethrough to said chamber.

9. In an air cleaner the combination of an upright filter, means for directing air upwardly through said filter, and means having an outlet beneath said filter for discharging a dust absorbing liquid into the air stream in advance of said filter to effect transfer and distribution of said liquid by the air into said i'llter, and means encircling said lter for receiving and carrying.

away liquid discharged from said filter.

10. In an air cleaner the combination of an upright filter, means for directing air upwardly through said filter, and means having an outlet disposed concentrically of and beneath said filter for discharging a dust absorbing liquid into the air stream in advance of said lter to effect transfer and distribution of said liquid by the air into said filter, and means encircling said filter for receiving and carrying away liquid discharged from said lter.

11. In an air cleaner for internal combustion engines the combination of a casing, a filtering medium therein, means for delivering oil for said lterlng medium, a conduit for connection with an engine carburetor to induce a flow of air through said casing and ltering medium, and a separate conduit for direct connection with the engine intake manifold for energizing said oil delivery means.

12. In an air cleaner for internal combustion engines the combination of a casing having a liquid reservoir in the base thereof, a filter-ing medium in said casing above said reservoir, means including a hydraulic air lift'for transferring liq.

uid from said reservoir to said illtering medium, a conduit for connection with an engine carburetor for inducing a flow of air through said casing and filtering medium, and a separate conduit for direct connection with the engine intake manifold for energizing said hydraulic air lift.

13. In an air cleaner for internal combustion engines the combination of a casing forming an air passage, means within said casing for extracting dust from the air passing therethrough, a liquid reservoir, an upright tube, the lower end of said tube projecting into said reservoir, a restricted passage through which liquid is admitted from said reservoir to the base of said tube, means for admitting atmospheric air to the base of said tube, means for subjecting the upper end of said tube to a partial Vacuum to thereby draw aerated liquid upwardly through said tube, and means for directing liquid supplied through said tube to said dust extracting means.

14. In an air cleaner for internal combustion engines the combination of a casing having a liquid reservoir therein, a filtering medium in said casing above said reservoir, a conduit for connection with an engine carburetor for inducing a flow of air through said casing and filtering medium, means supplied from said reservoir for delivering liquid into said flow of air, and a second conduit for direct connection with the engine intake manifold for energizing said last named means.

15. In an air cleaner for internal combustion engines the combination of a lter, means for connection with an engine carburetor for inducing a flow of air through said filter, and suction means for connection with the engine intake manifold independently of the carburetor for introducing liquid into said air ow.

16. In an air cleaner for internal combustion engines the combination of a filter, means for connection with an engine carburetor for inducing a flow of air through said filter, an oil reservoir, a chamber, a connection through which said chamber is exposed to suction Within the intake manifold of the engine independentlyl of the carburetor, means energized by the suction in said chamber for transferring liquid from said reservoir thereto, and means'for transferring liquid from said chamber into said air flow.

ARTHUR W. MLLER. 

